Mechanisms of Calmodulin Regulation of Different Isoforms of Kv7.4 K+ Channels.

@article{Sihn2016MechanismsOC,
  title={Mechanisms of Calmodulin Regulation of Different Isoforms of Kv7.4 K+ Channels.},
  author={Choong-Ryoul Sihn and Hyo Jeong Kim and Ryan L Woltz and Vladimir Yarov-Yarovoy and Pei-Chi Yang and Jun Xu and Colleen E. Clancy and Xiaodong Zhang and Nipavan Chiamvimonvat and Ebenezer N. Yamoah},
  journal={The Journal of biological chemistry},
  year={2016},
  volume={291 5},
  pages={2499-509}
}
Calmodulin (CaM), a Ca(2+)-sensing protein, is constitutively bound to IQ domains of the C termini of human Kv7 (hKv7, KCNQ) channels to mediate Ca(2+)-dependent reduction of Kv7 currents. However, the mechanism remains unclear. We report that CaM binds to two isoforms of the hKv7.4 channel in a Ca(2+)-independent manner but that only the long isoform (hKv7.4a) is regulated by Ca(2+)/CaM. Ca(2+)/CaM mediate reduction of the hKv7.4a channel by decreasing the channel open probability and altering… CONTINUE READING